Just as a note, all bootloaders that are not the binary built bootloader provided at download.rockbox.org are considered "unsupported builds." We provide a specific SVN revision compiled under specific condition so that we know what is to be expected because different versions of bootloader can have strange effects on the firmware (since some hardware initialization takes place there) so just like we don't support builds with patches, we don't support *any* bootloader or build running on a bootloader that isn't the one we provide, because we can't know that the bootloader isn't causing something strange to happen. Sometimes they're so quirky that even a different compiler version can completely break them, even when there are no changes to the code.

Sorry... I didn't get it. Are you saying that using alternative/modified bootloaders like this reverse one is not recommended?